Hydraulic apparatus

ABSTRACT

A hydraulic apparatus, such as a pump or motor, is contained within an elongated tubular casing having end heads closing opposite ends thereof. An elongated cylinder member is rotatably mounted within the casing and has a plurality of circumferentially spaced cylinder forming bores therein with an elongated piston member movably mounted within each bore, resilient means being arranged for urging the piston members outwardly relative to the cylinder member. Fluid intake or input and outlet flow means communicate with the cylinders for flow of fluid through the pump or motor. A cam or wobble plate is turnably supported on one end head and has piston-engaging portions in the form of a plurality of circumferentially spaced bearing members arranged to be in a plane at an acute angle to the longitudinal axis of the cylinder member whereby rotation of the cam plate effects or is in response to reciprocation of the piston members. The wobble or cam plate has portions thereon meshing with gear means on the adjacent end of the cylinder member for a positive driving connection therebetween for transmitting rotary motion between a power member and the cylinder member and cam plate.

United States Patent 72] Inventor Emmet G. Slusher PrimaryE.mminerWilliam L. lfreeh P.O. Box 472, Higginsville, Mo. 64037Attorney-Fishburn, Gold and Litman [211 App]. No 840,346 [22] Filed July9,1969 [45] Patented Aug. 31,1971

ABSTRACT: A hydraulic apparatus, such as a pump or motor, [54] HYDRAULICAPPARATUS is contained within an elongated tubular casing having end6Claims,6Drawing Figs. heads closing opposite ends thereof An elongatedcylinder 91 483 member is rotatably mounted wlthin the casing and has aplu [52] cl 91/501 rality of circumferentialiy spaced cylinder formingbores 1 Cl F02) 1/02 therein with an elongated piston member movablymounted [51] nt. F041) 1/22, wnhm each bore, resilient ea s bemgarranged for urgmg the piston members outwardly relative to the cylinder9 4 2, Flew 123/43 member Fluid intake or input and outlet flow meanscommumcate with the cylinders for flow of fluid through the pump or 5 kf mig motor. A cam or wobble plate is turnably supported on one UNITEDSTATES PATENTS end head and has piston-engaging portions in the form ofa 3 plurality of circumferentially spaced bearing members ar- 1,209,99512/1916 rd 5531/22 ranged to be in a plane at an acute angle to thelongitudinal 3,265,003 8/1966 ward l axis of the cylinder member wherebyrotation ofthe cam plate FOREIGN PATENT effects or is in response toreciprocation of the piston mem- 709,183 /1954 Great Britain.....103/162 bers The wobble or cam plate has portions thereon meshing1,007,446 10/1965 Great Britain... 103/162 with gear means on the adacent end of the cylinder member 885,008 5/1943 France 103/162 for apositive driving connection therebetween for trans- 593,597 9/1934Germany... 103/162 mitting rotary motion between a power member and the622,787 6/1961 Italy 103/162 cylinder member and cam plate.

I H 3% an 4/ l l3 12 38 e 39 I8 g a l 9 I 25 a z 2 \\Zs -40 ms 431, 3M93, 2 5! 4H 5 Ni n y I A." w it; i a w n PATENTEUAUGBI I9?! I 3,602,105

SHEET 2 [1r 3 VENTOR. Emma Slasher BY M, 00!

A TTORNE Y6 PATENIED M1831 l97| SHEET 3 0F 3 INVENTOR. Emme+ G. Slusher9W QJMU A TTOR NE Y6 HYDRAULIC APPARATUS The present invention relatesto hydraulic motors and pumps and more particularly to axial piston-typedouble-acting-type motors and pumps having piston-engaging bearingmembers rotatably mounted in canted cam plates operatively connected toa power member and a cylinder member having opposed pistons therein.

The principal objects of the present invention are: to provide an axialpiston-type hydraulic motor or pump wherein side thrust on reciprocatingpiston members is substantially eliminated; to provide such an axialpiston-type hydraulic motor or pump having rotatably mounted bearingmembers in piston-engaging faces of canted cam plates for cooperativeactuating relation to piston members reciprocably mounted in a rotatablecylinder member; to provide such an axial pistontype hydraulic motor orpump wherein the bearing members in the cam plate are circumferentiallyspaced and positioned to effect reciprocation of the piston members withresultant power transmission or pumping upon turning of the cylindermember; to provide such an axial piston-type hydraulic motor or pumpwherein the cam plate is operatively connected to an adjacent end of thecylinder member and to a power member for the resultant powertransmission or pumping; to provide such an axial piston-type hydraulicmotor or pump wherein both the piston members and the bearing members inthe cam plates are rotatable thereby providing substantially side thrustfree piston members; and to provide such an axial piston-type hydraulicmotor or pump which is economical to manufac' ture, easily maintained,simple in operation, positive and efficient in operation, andparticularly well suited for the proposed use.

Other objects and advantages of this invention will become apparent fromthe following description taken in connection with the accompanyingdrawings wherein are set forth by way of illustration and examplecertain embodiments of this inven tion.

FIG. 1 is a longitudinal sectional view of a hydraulic axial piston-typemotor or pump embodying features of the present invention,

FIG. 2 is a transverse sectional view through the motor or pump taken online 22, FIG. 1, showing fluid flow means.

FIG. 3 is a longitudinal sectional view of a modified hydraulic axialpiston-type motor or pump having a single cam plate.

FIG. 4 is a longitudinal sectional view of an other modified hydraulicaxial piston-type motor or pump wherein an adjust-- ment disc is movablebetween a maximum output and an idle position.

FIG. 5 is a transverse sectional view through the modified type motor orpump taken on line 55, FIG. 4, showing fluid flow means.

FIG. 6 is a longitudinal sectional view similar to FIG. 4 ex-- ceptshowing the adjustment disc in the idle position.

Referring more in detail to the drawings:

The reference numeral 1 generally designates a hydraulic apparatus, suchas a pump or motor, within an elongated, tubular, generally cylindricalcasing 2. End heads 3 and 4 close opposite ends of the casing 2 androtatably support cam or wobble plates 5 and 6 respectively. The camplates each have piston-engaging portions in the form of a plurality ofcircumferentially spaced bearing members 7 arranged in a plane at anangle to the longitudinal axis of the casing 2 with the bearing members7 being rotatably mounted in the cam or wobble plates 5 and 6 andpositioned to engage respective outer ends of a plurality of pistonmembers in the form of opposed piston portions 8 reciprocably mountedwithin cylinder forming bores 9 extending longitudinally through anelongated rotor or cylinder member 10 which is rotatably mounted withinthe casing 2.

In the illustrated structure, the end heads 3 and 4 each have a flange11 for engaging the respective opposite ends of the casing 2. End plates12 and 13 engage the flange 1 1 of the end heads 3 and 4 respectivelyand hold same in position closing the ends of the casing 1. The flanges11 and the end plates 12 and 13 each have a plurality ofcircumferentially spaced bores 14 for receiving tie rods 15 extendingtherethrough for holding the end plates 12 and 13 and the end heads 3and 4 in position tightly closing the opposite ends of the casing 2. Theend heads 3 and 4 each have inner ends or faces 16 and 17 respectivelypositioned within the casing 2 with each inner end having an annularrecess 18 and 19 therein for mounting suitable bearings 20 and 21 forrotatably supporting the cam plates 5 and 6 respectively.

One of the end heads, for example end head 3, has a bore 22 coaxiallyaligned with the longitudinal axis of the casing 2 and with thelongitudinal axis of the rotor or cylinder member 10. The end head 3 hasa counterbore 23 which has a suitable bearing 24 therein for rotatablysupporting a power member 25, as later described, extending through thebore 22 and counterbore 23. The end plate 12 has a central bore 26 forpermitting the power member 25 to extend therethrough and the end plate12 engages the bearing 24 holding same in the counterbore 23.

The power member 25 also extends through a bore 27 in the cam plate 5and in the illustrated structure, the power member 25 extends into alongitudinal axial central bore 28 of the rotor or cylinder member 10with the power member 25 being operatively connected therein.

The other end head 4 has a bore 29 axially aligned with the central bore28 and a counterbore 30 which has a bearing 31 therein for rotatablysupporting a valve shaft 32, as later described, which extends throughthe bore 29 and counterbore 30 into the central bore 28 for controllingfluid circulation within the rotor or cylinder member 10. The end plate13 has a central bore 33 for permitting the valve shaft 32 to extendtherethrough and the end plate 13 engages the bearing 31 holding same inthe counterbore 30, The valve shaft 32 also extends through a bore 34through the cam plate 6.

The rotor or cylinder member 10 is illustrated as an elongated,generally cylindrical barrel structure having the cylinder forming bores9 circumferentially spaced around the central bore 28. Suitablebearings35 are mounted on the exterior periphery of the rotor or cylinder member10 adjacent the opposite ends thereof and engage the inner periphery ofthe casing 2 for rotatably supporting same therein,

It is desirable to provide a positive connection between the rotor orcylinder member 10 and the cam plates 5 and 6 thereby substantiallyreducing or eliminating side thrust on the outer ends of the opposedpiston portions 8. Therefore, the opposite ends respectively of therotor or cylinder member 10 have gear teeth 36 and 37 forming ring gearsadjacent the peripheral edge thereof. Gear teeth 38 and 39 are providedon the cam plates 5 and 6 respectively adjacent their peripheral edgesforming ring gears meshing with the gear teeth 36 and 37 respectively,thereby providing a positive driving connection between the rotor orcylinder member 10 and the cam plates 5 and 6.

The hydraulic apparatus 1 will function as a pump when it is drivenmechanically and will function as a motor when driving fluid is suppliedbetween the pairs of opposed piston portions 8. For the purpose ofillustration, the apparatus 1 will be referred to herein as a motor andthe invention will be explained as applied to a motor for driving thepower member 25, however, the apparatus 1 may be used as a pump forpumping fluid therethrough by driving the power member 25.

In the illustrated structure, a fluid passage 41) extends between eachof the cylinder forming bores 9 and the central bore 28. Suitable fluidunder pressure is delivered to the fluid passages 40 through an input orinlet flow passage 41 extending longitudinally though the valve shaft32. The fluid passages 41) are positioned at the center of the rotor 10and communicate with the bores 9 between the opposed piston portions 8of the piston members. The input or inlet flow passage 41 has a port 42which communicates with a plurality of the fluid passages 40 for supplyof fluid between the opposed piston portions 8 thereby separating andurging same outwardly which turns the rotor 10 and the cam plates 5 and6. After the rotor turns through a portion of its rotation, fluid isdischarged from the cylinders 9 through the fluid passages 40 and intoan outlet flow passage 43 extending longitudinally through the valveshaft 32. The outlet flow passage 43 has a port 44 which communicateswith the fluid passages 40 that are not communicating with the inletport 42 whereby fluid is continually supplied to one portion of thefluid passages 40 and discharged from the remaining portion of the fluidpassages 40.

The valve shaft 32 is illustrated as an elongated tubular member havinga center wall member 45 therein for defining and separating the input orinlet and outlet flow passages 41 and 43. The input or inlet port 42 isillustrated as a slotted aperture in the tubular member with the inletslotted aperture extending between opposite edges of the center wallmember 45 at one face or surface thereof. The outlet port 44 is alsoillustrated as a slotted aperture in the tubular member with the outletslotted aperture extending between opposite edges of the center wallmember 45 at the other face or surface thereof. The slotted apertures 42and 44 are diametrically aligned and positioned at one end of the valveshaft 32.

When the apparatus 1 is operated as a motor, the power member 25 isdriven or rotated through its connection with the rotor or cylindermember 10 and the power member 25 is illustrated as an elongated shaftprojecting through and journaled in the end head 3, as previouslydescribed, and projecting coaxially into the central bore 23 in therotor 10 where one end thereof is operatively connected thereto as bybeing splined to the rotor or cylinder member 10, as indicated at 46,for transmission of rotary motion from the rotor or cylinder member 10to the power member 25.

The opposed piston portions 8 are movably and rotatably mounted withinthe cylinder formingbores 9 and the piston portions 8 each have outerends 47 thereof projecting beyond the outer or opposite ends of therotor or cylinder member 10. It is desirable to provide firm engagementbetween the cam plates 5 and 6 and the outer ends 47 of the opposedpiston portions 8 with the outer ends 47 firmly engaging the bearingmembers 7 with no direct connection therebetween. Therefore, suitableresilient members, such as heavy-duty, helical compression springs 48.are mounted within recesses 49 within facing ends of each of the opposedpiston portions 8 with the springs 48 being sized and wound to be undera load at all times thereby tending to separate the opposed pistonportions 8 and urging the outer ends 47 thereof outwardly from therespective opposite ends of the cylinder forming bores 9.

The bearing members 7 are each illustrated as a roller 50 mounted on anelongated axle 51 with opposite ends of the axle 51 being rotatablymounted in spaced ears 52 extending outwardly from each of the cam orwobble plates 5 and 6. The rollers 50 are arranged to be in a planecanted at an acute angle with the longitudinal axis of the cylindermember 10 whereby rotation of the cam or wobble plates and rotation ofthe cylinder member 10 effects or is in response to reciprocation of theopposed piston portions 8 within the bores 9. The outer ends 47 of theopposed piston portions 8 are shaped to provide smooth relative movementwhile in contact with the rollers 50. thereby substantially reducing oreliminating side thrust on the opposed piston portions 8.

The cam plates 5 and 6 are positioned in canted and opposed butsymmetrically acute angled relation with the Ion gitudinal axis of therotor or cylinder member 10 with the surface of the piston-engaging faceof the cam plates 5 and 6 intersecting the longitudinal axis of thecentral bore 28 diagonally and in opposed but symmetrical relation.

For maximum output, the supply input or intake port 42 for the intakefluid passage 41 is directed toward the fluid passage 40 communicatingwith the cylinder 9 having the opposed piston portions 8 thereinpositioned in the closest relation and with the cylinders 9 having theopposed piston portions 8 moving outwardly or in their expanding stroke.For maximum output, the outlet port 44 for the outlet fluid passage 43is aligned with the fluid passage 40 communicating with the cylinder 9having the opposed piston portions 8 in their farthest apart relationand with the cyiinders 9 having the opposed piston portions 8 movinginwardly or in their retracting stroke. In the illustrated structure,the top cylinder 9, as seen in FIGS. 1 and 2, has the piston portions 8at their closest together position and will be referred to as top deadcenter and the bottom cylinder 9, as seen in FIGS. 1 and 2, has thepiston portions 8 at their farthest apart position and will be referredto as bottom dead center.

To vary the output of the motor 1, the valve shaft 32 is rotated withinthe central bore 28, as by a handle 53, mounted on the other or exteriorend of the valve shaft 32. When the center wall member 45 extendsbetween top dead center and bottom dead center and the inlet flowpassage 41 is on the right, as seen in FIG. 2, the rotor 10 will turn ina clockwise direction, as seen in FIG. 2. When the central wall member45 is rotated clockwise or counterclockwise, as seen in FIG. 2, thedriving force on the rotor 10 will reduce until rotation stops and thenreverses. When the center wall member 45 is horizontal and the intakeflow passage 41 is at the top, as seen in FIG. 2, rotation will be atone-half speed and one-half torque. When the center wall member 45 ishorizontal and the intake flow passage 41 is at the bottom, as seen inFIG. 2, the driving force on the rotor or cylinder member 10 will be aminimum or zero.

Fluid is supplied to the input or intake fluid passage 41 through asuitable conduit 54 thereby rotating the rotor or cylinder member 10 byurging the opposed piston portions 8 apart. Rotation of the cylindermember 10 returns the fluid through the outlet fluid passage 43 to asuitable conduit 55 and rotation of the rotor or cylinder member 10.drives the power member 25 for transmission of power to a usingapparatus (not shown). The cam plates 5 and 6 are each turned in thesame direction or follow the rotation of the cylinder member 10 throughthe interengaging of the gear teeth. The power member 25 may be rotatedclockwise or counterclockwise by the positioning of the valve shaft 32with a larger portion of the intake or input port 42 of the intake orinput flow passage 41 to the right or left respectively of top deadcenter, as seen in FIG. 2.

FIG. 3 illustrates a modified hydraulic apparatus, such as a pump ormotor 66, within an elongated, tubular, generally cylindrical casing 61.An end head 62 closes one end of the casing 61 and rotatably supports acam or wobble plate 63 therein. Bearing members 64 are mounted on thecam plate 63 and arranged in a plane at an angle to the longitudinalaxis of the casing 61 with the bearing members being rotatably mountedon the cam plate 63 and positioned to engage respective outer ends of aplurality of piston members 65 reciprocably mounted within cylinderforming bores 66 extending longitudinally into an elongated rotor orcylinder member 67 which is rotatably mounted within the casing 61.

In the illustrated structure, the end head 62 has a flange 68 engagingone end of the casing 61 for closing same. An end plate 6? engages theflange 68 to hold suitable bearing members 70, as later described,within the end head 62. An end plate 71 engages and closes the other endof the casing 61. The end plate 69 and'end head 62 are maintained in aclosing relation with the one end of the casing 61 and the end plate 71is maintained in a closing relation with the other end of the casing 61by a plurality of tie rods 72 extending therethrough.

The cam plate 63 is canted at an acute angle with the iongitudinal axisof the casing 61 and has a ring gear 73 adjacent the peripheral edge ofthe cam or wobble plate 63 for meshing with a ring gear 74 on anadjacent end and adjacent a peripheral edge of the rotor or cylindermember 67, thereby providing a positive driving connection between therotor or cylinder member 67 and the cam or wobble plate 63.

In the illustrated structure, the cylinder forming bores 66 are recessesextending into the rotor or cylinder member 67. The bores or recesses 66have an end recess 75 of reduced diameter to form a socket for receivingone end of an -elon'- gated spring 76. The other end of the elongatedspring 76 is received within a recess 77 within the piston members 65for urging same outwardly from the rotor or cylinder member 67 therebymaintaining the piston members 65 in firm engagement with the bearingmembers 64.

A valve shaft 78, similar to valve shaft 32, it rotatably sup ported inthe end plate 71 for supplying fluid to and receiving fluid from thebores 66 in the rotor 67 and for controlling the direction of rotationof the rotor 67 and the speed and torque produced by the rotationthereof.

A power member 79, similar to power member 25, is rotatably supported inthe bearing members 70 within the end head 62 and is operativelyconnected to the rotor 67 whereby the power member 79 is rotated by therotor 67 when the modified hydraulic apparatus 60 is operated as a motorand the power member 79 rotates the rotor 67 when the modified hydraulicapparatus 60 is operated as a pump.

FIGS. 4, 5 and 6 illustrate a further modified hydraulic apparatus, suchas a pump or motor80, mounted within an elongated, generallycylindrical, tubular casing 81 having an input or intake port 82communicating with an input or intake channel 83 in the interiorperiphery of the casing 81 thereby defining an input or intake chamber.The casing 81 has an outlet port 84 also communicating with an outletchannel 85 within the inner periphery of the casing 81 thereby definingan outlet chamber.

An elongated rotor or cylinder member 86 is concentric within androtatably mounted within the casing 81 and has a plurality ofcircumferentially spaced cylinder forming bores 87 extendinglongitudinally therethrough. A fluid or flow passage 88 extends betweeneach of the cylinder forming bores 37 and an exterior periphery of therotor or cylinder member 86 for communication with the respective intakeand outlet channels 83 and 85. The channels 83 and 85 are concentricwith the outer periphery of the rotor or cylinder member 86 forcompactness of the casing 81 and smoothflow of the fluid through thefurther modified hydraulic apparatus 80.

End heads 89 and 90 close opposite ends of the casing 81, and one of theend heads, for example end head 90, has an adjustment disc 91 rotatablymounted therein with an axial shaft 92 extending outwardly therefromthrough a bore 93 in the one end head 90. The adjustment disc 91 has anannular recess 94 in an inner face thereof to rotatably support a camplate 95, as by bearings 96 mounted therein.

The cam plate 95 and a cam plate 97 which is rotatably mounted in theother end head 89 are normally canted at opposed but symmetrically,acutely angled relation with the longitudinal axis of the rotor orcylinder member 86 and with their respective inner or piston-engagingfaces intersecting the longitudinal axis of the rotor or cylinder member86 diagonally and in opposed but symmetrical relation. The cam plate 97has a shoulder 98 for engaging a bearing 99 mounted within an annularrecess 100 in one end of the other end head 89 for rotatably supportingsame therein.

A power member 101 extends outwardly from the shoulder 98 and isrotatably supported in the other end head 89, as by bearings 102 mountedin an annular recess 103 in the other end of the other end head 89. Aclosure flange 1 engages the other end of the other end head 89 and hasa central bore 195 through which the power member 101 extends and theclosure flange 1041 has a plurality of circumferentially spaced bores106 aligned with an equal number of bores 107 through a flange 108 atthe one end of the other end head 89. Each of the bores 106 and 107 arealigned with respective threaded sockets 109 in the casing 81 whereby atie rod 110 is mounted 'CIIICQCII of the aligned bores and threadedsockets to secure the closure flange 104 in engagement with the otherend of the other end head 89 thereby tightly closing same.

The adjustment disc 91 and the cam plate 95 rotatably carried thereinare adjustable to position said cam plate 95 in a position parallel withthe other cam plate 97 whereby when the modified hydraulic apparatus isemployed as a pump and it is desired to stop the pumping action thereofwithout stopping relative rotation of its parts, the adjustment disc 91is rotated 180 whereby the cam plates 95 and 97 are parallel, as

shown in FIG. 6. In this position, pairs of opposed pistons 111 shiftback and forth within the cylinder forming bores 87 with the turning ofthe rotor or cylinder member 86. However, there is no relative axialmotion between the opposed pistons 111 with the result that no pumpingoccurs even though the power member 101 continues to be driven.

In the illustrated structure, the axial shaft 92 has a suitable handle112 mounted thereon for turning the adjustment disc 91 to vary therelation between the cam plates 95 and 97 thereby adjusting the outputof the modified hydraulic apparatus 80 between the maximum outputposition and the parallel or idle position.

The cam plates 95 and 97 each have ring gears 113 and 1141 respectivelyadjacent their respective peripheral edges for meshing with ring gears115 and 116 on respective adjacent ends of the rotor or cylinder member86 thereby providing a positive driving connection between the rotor 86and the wobble or cam plates 95 and 97. A grooved recess or way 117extends into a portion of the inner periphery of the casing 81 toprovide clearance for the teeth forming the ring gear 114 during turningof the cam or wobble plate 97.

In the structure illustrated in FIGS. 4 and 6, the ring gear 114 isflush with an upper portion of the inner periphery of the casing 81 andthe way 117 extends around the lower portion of inner periphery of thecasing 81. The end head is sized to permit clearance for the ring gear113 during turning of the cam or wobble plate while in the positionshown in FIG. 1 or the position shown in FIG. 6 or any positiontherebetween without the necessity of providing a grooved recess or way.

It is to be understood that, while I have illustrated and describedcertain forms of my invention, it is not to be limited to these specificforms or arrangement of parts herein described and shown.

What I claim and desire to secure by Letters Patent is:

A hydraulic apparatus comprising:

an elongated tubular casing;

. end heads closing opposite ends of said casing;

. an elongated cylinder member rotatably mounted within said casing;

d. a plurality of circumferentially spaced cylinder forming bores insaid cylinder member with said cylinder forming bores extendinglongitudinally through said cylinder member;

e. an elongated piston member mounted within each of said cylinders,said piston members each having at least one end thereof extendingbeyond one end of said cylinder member; said piston members each havinga pair of opposed piston portions mounted within each of said cylinders,said piston portions each having one end thereof extending beyond arespective end of said cylinder member; fluid intake flow meanspositioned for communicating with said cylinders during a portion of therotation of said cylinder member for urging said piston members outwardly;

g. fluid outlet flow means positioned for communicating with saidcylinders during another portion of the rotation of said cylinder memberfor escape of fluid during inwardly movement of said piston members;

h. a cam plate turnably mounted on one of said end heads and havingpiston-engaging portions arranged in a plane canted at an acute anglerelative to "the longitudinal axis of said casing, each of said endheads having a cam plate turnably supported thereon;

. said piston-engaging portions of each of said cam plates are aplurality of circumferentially spaced bearing members rotatably mountedin each of said cam plates and positioned to engage said respective endsof said piston portions beyond said respectivecylinders;

j. said bearing members at said cam plates are arranged in planes cantedat opposed but symmetrically acutely angled relation with thelongitudinal axis of the cylinder member with said respective planeintersecting the iongitudinal axis of said cylinder member diagonallyand in opposed but symmetrical relation;

k. gear means associated with said cam plate and said one end of saidcylinder member and having meshing engagement for turning said cam platewith said cylinder member, said gear means being associated with each ofsaid cam plates and with opposite ends of said cylinder member, saidgear means on said cam plates meshing with said gear means on saidrespective opposite ends of said cylinder member for turning of said camplate with said cylinder member, said gear means urging each of said camplates to follow the rotation of said cylinder member whereby saidopposed piston portions of said piston members are reciprocated towardand away from each other within said respective cylinders;

l. a power member operatively connected to said cylinder member fortransmission of rotary motion therebetween.

. The hydraulic apparatus as set forth in claim 1 wherein:

. said cylinder member has a central bore extending longitudinallytherethrough;

b. said cylinder member has a fluid passageway extending between saidcentral bore and each of said cylinder forming bores, said fluidpassageways communicating with said respective cylinders at a pointbetween said opposed piston portions;

c. said cam plates are maintained at fixed angular relation with thelongitudinal axis of the cylinder member;

d. said fluid intake flow means and said fluid outlet flow means includean elongated tubular valve shaft coaxially and rotatably mounted withinsaid central bore and having inlet and outlet flow passages extendinglongitudinally therethrough, said inlet and outlet flow passages beingseparated by a center wall member and each having a port communicatingwith a plurality of said fluid passageways in said cylinder member; and

c. said valve shaft has adjustment means associated therewith forselectively positioning said inlet and outlet ports thereby controllingoperation of the hydraulic apparatus.

3. The hydraulic apparatus as set forth in claim 1 including:

a. an adjustment disc turnably mounted within one of said end heads andhaving one of said cam plates rotatably supported thereon; and

b. means associated with said adjustment disc for turning same between amaximum output position and an idle position, said maximum outputposition having said cam plates canted at an opposed but symmetricallyacutely angled relation with the longitudinal axis of said cylindermember, said idle position having said cam plates canted in a parallelrelation whereby there is no relative axial motion between said pistonportions.

4. The hydraulic apparatus as set forth in claim 3 wherein:

at said power member is an elongated shaft extending outwardly from theother of said cam plates whereby rotation of said cylinder member istransferred to said shaft.

5. The hydraulic apparatus as set forth in claim 3 wherein said fluidintake flow means and said fluid outlet flow means include:

a. an inlet flow channel in an interior surface of said tubular casing,said inlet flow channel being concentric with said cylinder member andextending around a portion of said interior surface of said tubularcasing;

b. an outlet flow channel in said interior surface of said tu bularcasing, said outlet flow channel being concentric with said cylindermember and peripherally aligned with said inlet flow channel, saidoutlet flow channel being separated from said inlet flow channel andextending around an other portion of said interior surface of saidtubular casing; c. a fluid passageway extending between each of saidcylinder forming bores and an exterior' surface of said cylinder member;d. an inlet port extending through said tubular casing and communicatingwith said inlet flow channel; and an outlet port extending through saidtubular casing and communicating with said outlet flow channel. 6. Ahydraulic apparatus comprising: a. an elongated tubular casing; b

. end heads closing opposite ends of said casing; an elongated cylindermember rotatably mounted within said casing;

d. a plurality of circumferentially spaced cylinder forming bores insaid cylinder member;

. an elongated piston member mounted within each of said cylinders, saidpiston members each having at least one end thereof extending'beyond oneend of said cylinder member;

. fluid intake flow means positioned for communicating with saidcylinders during a portion of the rotation of said cylinder member forurging said piston members outwardly;

g. fluid outlet flow means positioned for communicating with saidcylinders during another portion of the rotation of said cylinder memberfor escape of fluid during inwardly movement of said piston members;

h. a cam plate turnably mounted on one of said end heads and havingpiston-engaging portions arranged in a plane canted at an acute anglerelative to the longitudinal axis of said casing;

. said piston-engaging portions of said cam plate are a plurality ofcircumferentially spaced bearing members rotatably mounted on said camplate and positioned to engage said end of said piston members beyondsaid respective cylinders;

j. said bearing members each including a pair of ears mounted on saidrespective cam plate and extending outwardly therefrom, an elongatedaxle rotatably mounted on said ears, and a roller mounted on said axlefor engaging said respective ends of said piston members beyond ends ofsaid respective cylinders;

k. gear means associated with said cam plate and said one end of saidcylinder member and having meshing engage ment for turning said camplate with said cylinder member, said gear means urging said cam plateto follow the rotation of said cylinder member whereby said pistonmembers are reciprocated within said respective cylinders;

l. a power member operatively connected to said cylinder member fortransmission of rotary motion therebetween.

1. A hydraulic apparatus comprising: a. an elongated tubular casing; b.end heads closing opposite ends of said casing; c. an elongated cylindermember rotatably mounted within said casing; d. a plurality ofcircumferentially spaced cylinder forming bores in said cylinder memberwith said cylinder forming bores extending longitudinally through saidcylinder member; e. an elongated piston member mounted within each ofsaid cylinders, said piston members each having at least one end thereofextending beyond one end of said cylinder member; said piston memberseach having a pair of opposed piston portions mounted within each ofsaid cylinders, said piston portions each having one end thereofextending beyond a respective end of said cylinder member; f. fluidintake flow means positioned for communicating with said cylindersduring a portion of the rotation of said cylinder member for urging saidpiston members outwardly; g. fluid outlet flow means positioned forcommunicating with said cylinders during another portion of the rotationof said cylinder member for escape of fluid during inwardly movement ofsaid piston members; h. a cam plate turnably mounted on one of said endheads and having piston-engaging portions arranged in a plane canted atan acute angle relative to the longitudinal axis of said casing, each ofsaid end heads having a cam plate turnably supported thereon; i. saidpiston-engaging portions of each of said cam plates are a plurality ofcircumferentially spaced bearing members rotatably mounted in each ofsaid cam plates and positioned to engage said respective ends of saidpiston portions beyond said respective cylinders; j. said bearingmembers at said cam plates are arranged in planes canted at opposed butsymmetrically acutely angled relation with the longitudinal axis of thecylinder member with said respective plane intersecting the longitudinalaxis of said cylinder member diagonally and in opposed but symmetricalrelation; k. gear means associated with said cam plate and said one endof said cylinder member and having meshing engagement for turning saidcam plate with said cylinder member, said gear means being associatedwith each of said cam plates and with opposite ends of said cylindermember, said gear means on said cam plates meshing with said gear meanson said respective opposite ends of said cylinder member for turning ofsaid cam plate with said cylinder member, said gear means urging each ofsaid cam plates to follow the rotation of said cylinder member wherebysaid opposed piston portions of said piston members are reciprocatedtoward and away from each other within said respective cylinders; l. apower member operatively connected to said cylinder member fortransmission of rotary motion therebetween.
 2. The hydraulic apparatusas set forth in claim 1 wherein: a. said cylinder member has a centralbore extending longitudinally therethrough; b. said cylinder member hasa fluid passageway extending between said central bore and each of saidcylinder forming bores, said fluid passageways communicating with saidrespective cylinders at a point between said opPosed piston portions; c.said cam plates are maintained at fixed angular relation with thelongitudinal axis of the cylinder member; d. said fluid intake flowmeans and said fluid outlet flow means include an elongated tubularvalve shaft coaxially and rotatably mounted within said central bore andhaving inlet and outlet flow passages extending longitudinallytherethrough, said inlet and outlet flow passages being separated by acenter wall member and each having a port communicating with a pluralityof said fluid passageways in said cylinder member; and e. said valveshaft has adjustment means associated therewith for selectivelypositioning said inlet and outlet ports thereby controlling operation ofthe hydraulic apparatus.
 3. The hydraulic apparatus as set forth inclaim 1 including: a. an adjustment disc turnably mounted within one ofsaid end heads and having one of said cam plates rotatably supportedthereon; and b. means associated with said adjustment disc for turningsame between a maximum output position and an idle position, saidmaximum output position having said cam plates canted at an opposed butsymmetrically acutely angled relation with the longitudinal axis of saidcylinder member, said idle position having said cam plates canted in aparallel relation whereby there is no relative axial motion between saidpiston portions.
 4. The hydraulic apparatus as set forth in claim 3wherein: a. said power member is an elongated shaft extending outwardlyfrom the other of said cam plates whereby rotation of said cylindermember is transferred to said shaft.
 5. The hydraulic apparatus as setforth in claim 3 wherein said fluid intake flow means and said fluidoutlet flow means include: a. an inlet flow channel in an interiorsurface of said tubular casing, said inlet flow channel being concentricwith said cylinder member and extending around a portion of saidinterior surface of said tubular casing; b. an outlet flow channel insaid interior surface of said tubular casing, said outlet flow channelbeing concentric with said cylinder member and peripherally aligned withsaid inlet flow channel, said outlet flow channel being separated fromsaid inlet flow channel and extending around an other portion of saidinterior surface of said tubular casing; c. a fluid passageway extendingbetween each of said cylinder forming bores and an exterior surface ofsaid cylinder member; d. an inlet port extending through said tubularcasing and communicating with said inlet flow channel; and e. an outletport extending through said tubular casing and communicating with saidoutlet flow channel.
 6. A hydraulic apparatus comprising: a. anelongated tubular casing; b. end heads closing opposite ends of saidcasing; c. an elongated cylinder member rotatably mounted within saidcasing; d. a plurality of circumferentially spaced cylinder formingbores in said cylinder member; e. an elongated piston member mountedwithin each of said cylinders, said piston members each having at leastone end thereof extending beyond one end of said cylinder member; f.fluid intake flow means positioned for communicating with said cylindersduring a portion of the rotation of said cylinder member for urging saidpiston members outwardly; g. fluid outlet flow means positioned forcommunicating with said cylinders during another portion of the rotationof said cylinder member for escape of fluid during inwardly movement ofsaid piston members; h. a cam plate turnably mounted on one of said endheads and having piston-engaging portions arranged in a plane canted atan acute angle relative to the longitudinal axis of said casing; i. saidpiston-engaging portions of said cam plate are a plurality ofcircumferentially spaced bearing members rotatably mounted on said camplate and positioned to engage said end of said piston members beyondsaid respective cylinders; j. said bearing members Each including a pairof ears mounted on said respective cam plate and extending outwardlytherefrom, an elongated axle rotatably mounted on said ears, and aroller mounted on said axle for engaging said respective ends of saidpiston members beyond ends of said respective cylinders; k. gear meansassociated with said cam plate and said one end of said cylinder memberand having meshing engagement for turning said cam plate with saidcylinder member, said gear means urging said cam plate to follow therotation of said cylinder member whereby said piston members arereciprocated within said respective cylinders; l. a power memberoperatively connected to said cylinder member for transmission of rotarymotion therebetween.